Aircraft control



May 1945- v R. M. NARDONE 2,375,028

AIRCRAFT CONTROL Filed sept. 7, 1959 42 sheets-sheet 1 lNvENToR. RomeoM. /V fdo/7e May-1, 1945, R. M. NARDQNE 2,375,028

AIRCRAFT- CoNTHoL l Filed sept. 7,.'1939 2 4Sheets-Sheet 2 mechanismdisclosed in detail patent, above identilied.

Patented May l, 1945 oFFicE e Araoam CoNTaoL Romeo M. Nardone, EastOrange, N. 1I., assigner to Bendix Aviation Corporation, South Bend,Ind., a corporation of Delaware Applicat-in September 7, i939,Serial-No. 293,818

1 clarin. (c1. rapists) Tiflis invention relates -to aircraft, andpartieularly to the control of an aircraft engine vand theV propellerdriven thereby.,

Anobject of the invention is to provide novel l -means for controllingthepltch of the propeller as the'invention is disclosed herein, thecontrol means operates upon a propeller pitch changing mechanism of thecharacter described in Martin Patent No. 2,081,948, andlseifective toturn the propeller blades beyond the normal pitch range arc, by reasonof the development of considerably higher uid pressure than that ofwhich the engine driven pump of the Martin patent system would becapable (particularly if there should be a failure of engine parts); thehigher pressure being in turn produced by driving a field-compressor orpump through independent means, as by connection thereof to the armatureshaft of a high speed motor suoliasithat commonly incorle'ading to thecylinder 22; said valve in housing 23 being preferably identical instructure and the propeller, that is, for operation in normal mode ofoperationv to the valve 38` illustrated in Fig. 2 of the Martin etal.patent.

Thepressure iluid supplying means just de y scribed is stuilcient forthe normal operation of flight, with the' associated engine I Ugenerating power normally and with the pitch of the blades variable overthe normal, limited range.

There will next be described the auxiliary pressure uid'supplying meansadapted to be brought into operation in an emergency to increase theporated in enginne starter mechanism, one such mechanism beingillustrated in the aocoinpaeuiying draw i. 1 s wherein;

Fig. l is a diagrammatic view of arsystem embodying the presentinventiom' Fig. 2 is a transverse view along line 2 2 of rig. i; and

sie. a is e schematic View of a modified type of drive for the pump ofthe system of Fig. 1.

In the various views the numeral l0 generally indicates a. power plantof the'internal combus Y tric motor El having an armature' shaft 33nortion engine type, and including a controllable pitchpropeller.generallyindicated at I2, having two or more radially disposed blades I4rotatably mounted at their root or base ends in a hub barrel member i6for pitch changing movement about their longitudinal axes. The pitchangle of the blades M isr'controlled by a pair of centrifugally actuatedcounterweights I8 directly connected to the respective blades and ahydraulic mechanism 2li operatively connected to the counf I terweights;this being the type of pitch changing invMartin` et al.

As in the Martin et al. patent, the counterweights tend to turn theblades i4 in one direction,

and the movablecylinder 22 of the hydraulic is operative to overcomethis tendency -f and turn theblades in the oppositedirection, the

i Ahydraulic pressure for this Vpurpose beingV normally roduced throughoperation oifthe engine `driven ump l pumping oil from the source '2l ata ratefwhich varies according to the setting lo1' a' governor operatedvalve located in a housing -23 of the aforesaid and controlling deliveryof o il to the conduit Il force applied to cylinder 22A and therebyswing the blades beyond the normal range. As shown.

such auxiliary means includes a second' pump 28 adapted to receive oilfrom source 2l, as by way of supply pipe 2S, and pumpsuch oil to thecylluderY 22, as by way of conduit 30. This pump is normally idle. butinan emergency can beenergized'to operate to develop apressure far inexcesa of the' capacity of pump P; and from a source of power that is'available even though the engine such failure,

lll has failed and, in consequence of is delivering no power whatever.-

This source of power for operation of pump 28 islshown in Fig. 1 asinvolvlng'a'high' speedfelecmally coupled to flywheel 34 of an enginestartermechanism, but adapted to be drivably connected to the pump 28through operation of coupling linkage indicated in Fig. 2 and also inFig. l just below the section line 2--2.V The engine starter includes anengine engaging clutch member 36 and a speed reducing gear train whosehigh speed l end is constituted by a pinion 39 rotatable with:

flywheel 34, and whose low speed end consists of v a gear Il adapted torotate a barrell housing a preset clutch of the overloadyieiding type(such asillustrated in detail in Lansing Patent No.A 1,833,948) 'wherebyrotation is imparted to the engine 'engagingclutchl element 36. Movementofthe' clutch element 36 into engagement with correspondingclutchelement 3l of the engine is under the control of axially moyablerod 38 passing centrally and slidably through clutch barrel 42andconnecting with clutch member A36 through yieldable means in theaforesaid Lansing patent or directly as indicated. The Vrod is normallyre,`

strained in. the clutch retracting position shbwn by suitable means suchas coiled torsion spring the coiled torsion' spring |86 Y Lansingpatent, and is movable into the clutch meshing position .by manualmeans, if desired,or by euergization of a solenoid 43 corresponding towhose plunger 5| connects with rod 38 lby way of the intervening levers52 and 53 and the rock shaft 54 about which the spring 43 is coiled. Thewinding (not shown) of this meshing solenoid may be interposed in'acircuit (not shown) from a suitable source. which source and circuit mayalso include, bymeans of parallel connections, the windings of theelectric motor 32.

In case of motor failure (or if the source of current is temporarilyinsufficient) the starter may be operated by accelerating the flywheel34 manually through the instrumentality of the manually rotatable shaft35 connecting with the starter gear train as indicated at 58 and 51.

As shown in Fig. 1 the connection between the motor armature shaft 33and the ywheel. 34 takes the form of an externally splined sleeve orclutch element 66 normally meshing with two internally splined elements6| and 62, the former being integrated with the flywheel 34, as byscrews 63, and the latter being integrated with the armature shaft 33. Acoiled compression spring 84 bears at one end against the base of thesocketed part of amature shaft 33, and at its opposite end. exertspressure on clutch element 66 to hold the latter in the meshed positionshown. A rod 61 slidably extends through armature shaft 33 andoperatively connects with lclutch 86 as by means of a key 68, wherebyrearward sliding of rod 61 will draw clutch 68 to the right andinterrupt driving relationship between armature shaft 33 and flywheel34, and at the same time establish driving relationship between the saidarmature shaft 33 and the gear train leading to and operativelyconnecting with the rotor of the propeller feathering pump 28.

To bring about such rearward movement of rod 61 there is provided abifurcated lever 1| straddling the rodA 61 and abutting the hub of agear 12 secured by suitable means to the rear end'of said rod, where thelatter protrudes beyond the-bearing and retainer assembly 14 at the rearof armature shaft 33. Supports 18 provide pivotal mounting for lever 1|,and a rocking thereof about pivot bearing 11 isV eected by reciprocationof a bar at 18. As shown in Figs, 1 and 2 this bar 18 is slidablyreceived in the upper portion 18 of the motor housing and includes anotch 8| having a cam edge 82 (Fig. 2)

engageable with the upper endY 83 of lever 1| torock the latter inresponse to a pull exerted upon the bar actuating cable 84 in thedirection of the arrow in Fig. 2. 'I'he gear train 86. 81, 88 is therebycoupled for rotation with the armature shaft of the motor 32 and servesto produce rotation of the rotor of-the pump' 28 at a speed proportionalto that of the motor 32. there being preferably some speed reductiontherebetween and the gear sizes for the elements 86, 81,'and

88 being so chosen as to achieve this end.

Where the engine whose propeller is to be controlled is equipped with astarter of the type (see Fig. 3) in which the engine-engaging member(see element 91) moves into mesh with the.

crank-shaft connected member 82 -by the automatic action of a screwmechanism 83 in response to rotation 0f the driving motor .84 inlthe-engine starting direction, the same motor 84 may be utilized tooperate the pump 28 of the system of Fig. l, and may be made effectivefor this purpose by providing it with a reversibility characteristic (asby use of alternately energizable field windings 86 and 81) and anoverrunning clutch 88 Whose inner race is integrated with the motorshaft 98, and whose outer race is integrated with one element of thepumpdriving gear train IDI, corresponding to the gear train 8B, 81, 88of Fig. 1.

With an installation as shown in Fig. 3, movement of switch |82 from theoiT position to position S (starting) will cause current to flow fromsource |83 to motor 84 in a direction to cause starting of the engine,while rollers. |04 of Vthe clutch 88 over-run, that is, roll freely intheir pockets without causing any rotation of the outer race of theclutch, hence no movement of pump 28; subsequent movementas in the eventof a stall of the engine-from neutral to position F will cause currentto flow to motor 84 in the opposite direction, whereupon clutch 88becomes effective to operate the pump 28 to vary the pitch of thepropeller through operation of the'iluid connections shown in Fig. 1.During such operation screw mechanism 83 operates to hold clutch 8| outof engagement with element 82, due to the reversalof the'normal threadaction.

If desired, uni-directional screw drives of the character shown at 93 inFig. 3 may be employed at opposite ends of the armature shaft of motor84, and so arranged that one becomes effective to couple the motor tothe flywheel 34, or other part of the engine starting mechanism, uponright-hand rotation, for example; and the other may become effective tocouple the motor to the pump 28 upon left-hand rotation.

What I claim is:

In combination with an 'internal combustion 40 engine propeller having ahub with blades journaled thereon, the pitch of which blades is variablein one direction by centrifugal force produced by rotation of thepropeller, means includin'g an engine driven pump for introducing liquidunder pressure to the interior of said hub to overcome the action ofcentrifugal force and to turn the blades in the opposite direction,means including asecond pump for introducing liquid under higherpressure to turn the blades beyond their normal range, means includingan engineengaging member andan electric motor for impartinginitialrotary movement to the enginepropeller, means including a unidirectionalclutch `of the jamming roller type and spur gearing for drivablyconnecting said electric motor with said second pump, means responsiveto rotation of said electric motor in one direction to cause movement ofsaid engine-engaging member to engineengaging position, and a consequentunitary rotation of said engine-engaging member and engine propellerindependently of any rotation of Asaid second pump. and means forreversing the direction of rotation of said electric motor to causerotation of said second pump through the agency 4of said unidirectionalclutch, and independently of any movement of said engine-engaging memberto engine-engaging position.

ROMEO M. NARDONE.

